Cutter head



May 24. 1921,

C. WOLF. f

Filed Feb. 17. 1926 uuml Patented May 24, 1927.

UNITED STATES PATENT OFFICE.

CHARLES WOLF, OF BELOIT, WISCONSIN, ASSIGNOR TO YATES-AMERICAN MACHINE COMPANY, OF BELOIT, WISCONSIN, A CORPORATION OF DELAWARE.

CUTTER HEAD.

Application filed February 17, 1926. Serial No. 88,789.

My invention relates to cutter-heads or cylinders, such as are commonly employed in wood-working machines, and which are rotated at high speeds, thus subjecting their parts to substantial centrifugal strains in addition to those imposed by the cutting or planing operation itself.

One aim of the present invention is the provision of a cutter-head of this type having no holding bolts or screws for the knives, which are subject to supplemental tension or strain due to the action of the centrifugal force, hence eliminating a source of breakage and danger present in earlier constructions.

An object of the invention is the production of a structure of this kind in which all of the parts may be easily and economically machined, hence maintaining a good balance essential where high rotational speeds are employed.

In the new cutter-head. in the preferred embodiment of the invention, the knife is clamped or held between two parts or walls both integral with the knife-carrier, thus doubling the usual holding friction obtainable.

Such knife-carrier has no separate washers, plates or other similar loose parts, eX- cept the holding screws, which are ordinarily in use maintaining the knives and their carriers securely in position.

The construction is such that if the knifecarrier holding screw becomes loose, or through accident or misadvertence is nottightened, the carrier cannot come out of or free itself from the rapidly-revolving cutterhead, hence assuring safety even at high speeds.

A further purpose of the invention is to supply a cutter-head of such construction that the greater the centrifugal force present, the tighter the knife-carrier wedges itself in, and this in no way depends upon the safety of a holding screw or similar means.

Another added salient characteristic of a cutter-head incorporating the present invention resides in the fact that the thrusts of the knife in action are amply and adequately cared for without danger of weakening 01 breakage of the parts involved.

In order that those skilled in this art may understand how the above specied and other advantages are had in the new structure, in the accompanying drawing, forming a part of this specification, and throughout the views of which like reference characters have been employed to designate the same parts, a present preferred embodiment of the invention has been shown in detail.

In this drawing Figure 1 is an end elevation of a cutterhead of this character;

Figure 2 is a fragmentary detail section along one of the knife-carrier receiving grooves, showing one such carrier and its knife or cutter in place.

Figure 3 is a fragmentary section showing a modified style of screw securing means for the base of the knife-carrier.

By reference to this drawing, it will be perceived that the cutter-head or cylinder 1l has a' plurality of parallel longitudinal grooves 12 on its outer cylindrical surface, each such groove having an inner wall or face 13 at its ends joining longer and shorter walls 14 and 15 substantially parallel to one another and both oblique to the wall 13, as is clearly shown.

The longer inner wall or surface 14 joins an outstanding wall 16 forming an overhanging shoulder or abutment substantially parallel to the wall 18, the outer end of the face 16 joining an outwardly directed surface or wall 17.

On the other hand, the shorter oblique surface 15 connects with a narrow face 18, which directly joins with an outwardly disposed external surface 19 practically parallel with the face 16.

From an understanding of this construction, it will be seen thatV each groove 12 is undercut along both longitudinal margins and that it has an inclined or sloping face 15 which may act as a wedging surface, the broad face 19 affording a rm and solid base for the Support and reinforcement of the associated knife-carrier.

Those skilled in this art will understand that one or more of the knife-carriers or cutter-supports may be slid in each of the several grooves from the end of the cutterhead and securely fastened therein at the proper locatons.`

Each such carrier or support 21 has a base 22 with upper and lower parallel surfaces 23 and 24 designed to underlie and overlie the shoulders 16 and 19, respectively, and

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to bear thereon, such base having a lower or inner extension 25 shaped to conform to the groove 12 and to project under the sloping or oblique surface l5, such rib Q having the faces 2G, 27 and 28, the latter eX- tending up and forming the end sloping surface of the base 22.

VIn order to wedge the surface 26 of the carrier beneath and firmly into contact with the companion or correlated face 15 of the cutter-head, the base 22 has one or more threaded holes or apertures 29 extended transversely or crosswise therethrough parallel to the faces 16 and 19, each such hole accommodating a set or holding screw 31 having a conical inner end pressing against the surface 14 to force the carrier outwardly or crosswise under the overhanging shoulder fitted with the co-operating wedge surface 15.

The external or accessible end of the screw has the usual slot or recess for the reception of the end of a screw-driver, whereby the screw may be easily turned to perform its specified function.

The base Q2 of the carrier has a pair of upstanding, spaced plates or walls, inner and outer sections 3Q and 33, both integral with the base and designed to receive between them the knife or cutter 34, which, of course, projects outwardly beyond them to perform its cutting action.

To position such cutter obliquely to its work, these companion walls are disposed aslant to their hase and the cutter-head, as can be readily seen from the drawing.

Such separated knife-clamping walls are aperturcd in register at one or more points, the holes in the outer walls being screwthreaded to coact with a corresponding number of tightening or clamping screws 35 whose head or heads, as the case may be, bear against the inner face of the wall 3Q, the knife or cutter being slotted at 36, as shown in Fig. 2, so that they may be inserted in and withdrawn from the slots or spaces between such walls without requiring the screws to be taken out, although, of course, they must be loosened to permit interchange of knives.

lnasmuch as these two walls are both integral with the base, and since they bear on opposite sides of the knife, an unusual or double holding action thereon is secured, it being understood that under the tightening action of the screw or screws. these walls can be bent or deflected slightly but yet sufficiently to securely and firmly clamp or nold the knife in place.

Hence each knife is not only immovably and tixedly clamped to its carrier, but the latter is wedged in the cutter-head groove in such manner that it is very firmly maintained in position. the co-operating faces 19 and 24 of the cutter-head and knife-carrier coacting to support the latter' and its knife elliciently and effectively in working position.

lVithout reverting to or repeating the principal advantages incident to the employment of a construction of this character, those acquainted with this art will readily understand how the specified advantages are obtained in the improved construction illustrated and described in detail.

The scope of this invention is defined by the appended claims, but it is to be remembered that many more or less radical changes may he incorporated in the construction presented without departure from the heart and essence of the invention and without the sacrifice of any of its material benefits and advantages.

For example, instead of having the tapered or conical end of screw 31 press on the surface 14 directly, the corresponding screw 131 (Figure 3) may be made somewhat shorter and bear on a. pin or rod slidable in a cylindrical cavity in the base 22 and designed to bear at its outer end on the surface 14, the member 100 being prevented by any approved means from sliding out of its recess when the knife-carrier is removed from the cutter-head.

I claim:

l. A cutter-head having an undercut groove in its surface and a face external to said groove, in combination with 'a knifecarrier in said groove having a transverse wedging engagement with a wall of lsaid groove and having a surface bearing on said cutter-head face, and means tending to increase said wedging action by moving said carrier crosswise of said groove.

2. A cutter-head having an undercut groove in its surface and a face external to said groove, in combination with a knifecarrier in said groove having a transverse wedging engagement with a wall of said groove and having a lsurface bearing on said cutter-head face and having a transverse screw-threaded hole therethrough, and a screw in said hole engaging a wall of said cutter-head and tending to increase said wedging action by forcing said carrier crosswise of said groove.

3. A cutter-head having an undercut groove in its surface, one of the overlying parts of the cutter-head forming Isuch groove having an external face and an internal wedge surface oblique with relation thereto, in combination with a knife-carrier in said groove having a shoulder in engagement with said external face and a wedge surface engaging said oblique wedge surface, and means tending to increase the wedging action between said wedge surfaces by moving said carrier crosswise of said groove.

4. A cutter-head having an undercut groove in its Surface formed by opposite inwardly-directed overlying parts of the cutter-head along the opposite longitudinal margins of the groove, one of said parts having an external face and an internal wedge surface oblique with relation thereto, in combination with a knife-carrier in said groove having a shoulder in engagement with said external face and a wedge surface in contact with lsaid oblique wedge surface, said knife-carrier having a transverse screwthreaded hole therethrough, and a screw in said hole engaging a wall of said cutter-head and tending to increase the wedging action between said wedge surfaces by forcing said knife-carrier crosswise of said groove.

5. A cutter-head having an undercut groove in its surface and a face external to said groove, in combination with a knifecarrier in said groove having a transverse wedging engagement with a wall of said groove and having a surface bearing on said cutter-head face, means tending to increase said wedging action by moving said carrier crosswise in said groove, said knife-carrier having integral therewith a pair of spaced walls adapted t receive a knife between them, and means to clamp a knife between said walls.

6. A cutter-head having an undercut groove in its surface formed by opposed inwardly-directed overlying partsof the cutter-head along the opposite longitudinal margins of the groove, one of said parts having an external face and an internal wedge surface oblique with relation thereto, in combination with a knife-carrier in said groove having' a shoulder in engagement with said external face and a wedge surface in contact with said oblique wedge surface, said knifecarrier having a transverse screw-threaded hole therethrough, a screw in said hole engaging a wall of said cutter-head and tending to increase the wedging action between said wedge surfaces by forcing said knifearrier crosswise of said groove, said knifecarrier having a pair of integral spaced walls adapted to receive a knife between them, the outermost of said walls having a screw-threaded hole therein and the innermost of said walls having a hole in register therewith, and a screw adapted to clamp a knife between said knife-carrier walls extended through said unthreaded hole and engaging the screw-threads of the other hole.

n Witness whereof I have hereunto set my hand.

CHARLES WOLF. 

